The present invention generally relates to the swivel-assistance to a roof-skin holding bow forming the lower end of a folding canopy and more particularly to a space saving arrangement for swivel-assisting rod elements.
A swivel-assistance of the type concerned here can be taken as already known from German Published Unexamined Patent Application No. 1,630,305. In this prior art, one approximately horizontally arranged hydraulic cylinder, having an end facing away from the main hoop which is articulated on a bearing block fixed to the bodywork, is situated on either side of a motor vehicle in the limbs of a canopy compartment. By subjecting the hydraulic cylinder to pressure, this taking place automatically under control by fluidic limit switches, the roof-skin holding bow and, together with the latter, the rear part of the canopy is swung up forwards or folded back into its approximately horizontal starting position, in accordance with requirements. During this procedure, the main hoop, to which the lateral limbs of the roof-skin holding bow are affixed, retains its raised, essentially vertical position.
To lower the folding canopy into the canopy compartment, the main hoop can be tilted over, being driven to swivel by two hydraulic cylinders which are associated with the two canopy struts of the main hoop, act on the latter and are likewise supported by being fixed to the bodywork. During this procedure, the hydraulic cylinders which are articulated on the main hoop retract and simultaneously push the piston rods of the corresponding hydraulic cylinders articulated on the holding bow into their cylinders.
Because of the automatic sequential control of the folding of all canopy parts, a high degree of user convenience is already ensured. However, this is achieved at the price of accepting the need for a considerable installation and movement clearance in order to accommodate the two hydraulic cylinders near to the canopy compartment and this has a disadvantageous effect, in particular on the overall depth of the sideboards of the vehicle.
Thus it is an object of the present invention to provide swivel-assistance of a roof-skin holding bow of a folding canopy in such a way that a space-saving arrangement of the swivel-assisting rod elements is possible.
According to the certain advantageous features of preferred embodiments of the present invention, the second end of the rod element is connected in articulated fashion to the associated canopy strut. Thus, as seen in the transverse direction of the folding canopy, it is possible to arrange the rod element next to the lower longitudinal section of the canopy strut. In addition, by reason of its articulation, the rod element participates in all swivelling movements of the main hoop, with the result that its position relative to the canopy strut changes slightly only in the course of its own length alteration. In order to avoid deformations of the roof-skin holding bow by the assisting forces of the rod element, the bilateral swivel-assistance of the roof-skin holding bow will in general be expedient, i.e. the allocation of two rod elements of equal assisting force to the two lateral limbs of the roof-skin holding bow.
Advantageous further developments of the subject-matter of the invention will be apparent as the description of the invention and its embodiment proceeds.
It is to be regarded as advantageous if the length of the rod element is fixed at the supporting length it exhibits when the roof-skin holding bow is raised. In this case, the length-locked rod element can simultaneously serve as a guide, which, in cooperation with further linkage members, can assume the mechanical obligatory control of the roof-skin holding bow in the longitudinal direction of the vehicle which is necessary for lowering the folding canopy into the canopy compartment.
For fixing the length, mechanical engagement devices which, in the simplest case, can be manually actuatable, are envisioned.
However, automatically locking rod elements, which do not require any intervention, are to be recommended. Such rod elements, which are also used as openers for tailgates or the like, in the form of so-called gas-filled spring devices, are generally known. An example of a prior art publication which may be mentioned here is German Patent No. 2,513,302, which discloses an automatically lockable pneumatic or hydropneumatic telescopic spring.
However, rod elements whose length can be altered under spring force have the disadvantage that they can only have an assisting effect in one swivelling direction of the roof-skin holding bow, while, in the opposite direction, they inhibit the advance.
It is therefore preferable to provide a double-acting working cylinder as rod element. The latter is particularly true when a pressure and/or suction source which can also be used for loading the working cylinder is present anyway for automatic canopy actuation. In this case, however, a hose permanently connected to the working cylinder is required for the working medium, the hose being connected to the pressure and/or suction source. The flexible hose must here be laid such that it can compensate for the relative movements with respect to the bodywork without being pinched off or damaged. It is particularly simple to lay the hose in this way if the working cylinder is arranged in the clear fork cross-section of an end region, near the main bearing, of the associated canopy strut. In addition, this type of arrangement results in a particularly compact accommodation of the rod element.
To convert the advance of the rod element into a swivelling movement of the roof-skin holding bow, however, a connecting lever fixed to the holding bow must be present between the fork faces of the canopy strut, while the end region of the lateral limb, due to its function, must lie further out than this clear canopy strut cross-section which accommodates the rod element. For this reason, an arm which is connected rotationally fast to the mounted end of the lateral limb is swivel-mounted between the fork faces at the articulation point of the roof-skin holding bow on the main strut. Customary transmission linkages are suitable for the rotationally fast connection.
It is possible to dispense with rod elements which can be fixed in length, if the roof-skin holding bow itself is held under a spring loading in its lowered position against associated stops, said position lying approximately parallel behind the roof-skin holding rails.
If the rod elements provided are gas-filled spring devices or similar compression spring arrangements, these can simultaneously be used as well for the desired spring loading by being articulated under an overcenter arrangement.
Because of the tolerance-compensating effect of this principle, inexpensive rod elements can be used here.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.